Have you uploaded all your music into Google's Play Music cloud to enjoy your music from wherever you are, from any device? In this case, make sure you are not using more than 10 different devices - per year (which is a pretty tough limit for reviewers and gadget addicts). As Phil Nickinson from Android Central posted yesterday on Google Plus, Google has introduced a new deauthrization limit which allows users to get rid-off unused devices. In general, the Google Play Music library is accessible from any computer and up to ten devices and at this time only two Google accounts per computer can be used to add music with the Google Play Music Manager.

So far so good but what happens if you are going to use your 11th device? You have to unauthorize one of the first 10 devices to get free space to authorize the 11th. However, Google has recently changed the terms and conditions and is now allowing to revoke access of four devices per year only.

While Google says it identifies devices by the computer's MAC address or device identifiers such as IMEI or MEID for mobile devices, the limit of only 4 devices per year is pretty strict. Imagine you have to replace your LAN or card on your computer, the same computer becomes a second device and changing the computer after is a third device. While it seems that reflashed devices are not affected at all, because Google is using the device's unique IMEI number, it happens that the same device appears a second or even a third time after it was flashed. Doesn't matter if it was flashed with custom ROMs or with stock ROMs.

So far it seems that there's no workaround available and even Google's second level support is unable to help users with more than 10 devices but being allowed to unauthorize 4 devices per year only means it needs 2.5 years to get rid of all previously used devices. Google has definitely to find another way to protect rights owners interests.

In the meantime, it might be a good idea to create a second Google Play Music account and mirroring your music collection there or using mSpot instead, which also comes with restrictions but at least allows to deauthorize any device, anytime.

UPDATE 17.07.12: Looks like Google got some negative comments and therefore went back to the previous status - for now: "Yesterday we made a change to our device policy for music on Google Play, [...] and you may do this up to four times per year.We limit the number of times you can swap out new devices at the request of some of our music partners in an effort to limit abuse. We understand this has caused some issues for users who often deauthorize and reauthorize the same device, and we are currently re-implementing the solution in a way that works for our users and music partners.We apologize for any inconvenience and will update this page as new changes are made."

So any Google Music user might better hurry up and deauthorize as much as possible devices from the account since it looks like this won't last for too long. But don't deauthorize your main PC from where you upload your tracks to the cloud.